Study On Quantum Audio And Image Encryption Algorithms

Multimedia information as an important resource, its security has become the focus of people. With the progress of information technology and the in-depth study, although some researchers have developed many encryption schemes, most encryption schemes have been confirmed to exist some defects, inefficient, having poor encryption effect, vulnerable to various attacks. Digital audio and digital image as the two important forms of information carrier, the research on them becomes the foundation of other multimedia data protection. Therefore, strengthening the protection of the audio and image information has become urgent to solve the problem, which has great theory significance and practical value.Quantum computation as a new branch, constantly attract people’s attention and research. With the development of quantum computation, information processing is naturally extended to quantum field. As a new computing model, quantum computation can utilize quantum mechanical entanglement superposition characteristics to storage, processing and transmission of data information. In this paper, we consider the combination of quantum mechanics and information communication, to take advantage of the special properties of quantum computation to make up the defects and shortcomings of classical encryption algorithm.This paper mainly applies the quantum encryption algorithm to digital audio and digital image field. The main research achievements are as follows: 1) We propose an encryption algorithm of digital audio based on quantum. The algorithm by introducing the quantum representation model of audio, and then utilizing the double random phase encoding technique(Double Random Phase Encode, denoted as DRPE), encrypting the audio information in the spatial domain and the quantum Fourier domain respectively. Only by getting both the encryption key of spatial domain and Fourier domain, can we recover the original audio data. According to the reversibility of quantum computing unitary operation, the decryption process is the inverse of the encryption process. Taking advantage of the characteristic of quantum computation, the proposed scheme will greatly improve the efficiency and security of audio encryption. Compared to the classical encryption technique based on double random phase encoding, the encryption scheme based on quantum has great advantage on security, robustness, and computing complexity. 2) We propose an image encryption compression algorithm based on quantum random walk(denoted as QRW) and Chinese remainder theorem(denoted as CRT). By using quantum random walk’s nonlinear dynamic characteristic, we can generate a series of random data, and after the transformation and filtering we can get the image encryption key. The original image and the encryption key have a XOR operation and an Arnold transform, then obtain the encrypted image. Based on the properties of Chinese remainder theorem, the image can be compressed with a given compression ratio k, finally getting the encrypted compression image. The biggest advantage of this algorithm is theoretically generating an infinite key space to resist the brute force attack, thereby preventing the illegal user steals the image. Finally through the analysis of the statistical characteristics, random, encryption quality, compression performance of the encryption image, we can found that, this scheme has a better security and compression properties. 3) We propose a gray level image encryption algorithm based on one-dimensional quantum cellular automata(denoted as QCA). The quantum image encryption process can be realized by subtly constructing the evolution rules of one-dimensional quantum cellular automata. The novel enhanced quantum representation model is used to reduce the time of preparing the quantum images, which is better than the flexible representation of quantum images model used in existing quantum image encryption schemes. Numerical simulation and experiment show that, the security and computational complexity of the proposed encryption algorithm is better than the classical cellular automata scheme and QFT scheme.